Fabric adhesives are often used on fusible interlinings, which are materials such as fabrics which have been coated on one side with a discontinuous pattern of adhesive. When the interlining is bonded to a face fabric in a garment, it provides body and shape to the garment without impairing the ability of the fabric to breathe. Fusible interlinings are used in the manufacture of suits, in shirt collars and cuffs, and in the waistbands of trousers. In the manufacture of suits, polycarbonate basting threads are frequently used to temporarily hold the parts of the suit in place. After the suit is completed, a solvent such as perchloroethylene or trichloroethylene is used to embrittle the polycarbonate thread so that it may be brushed from the fabric.
In attempting to make polyesters from linear aliphatic or cycloaliphatic dibasic acids such as adipic acid or 1,4-cyclohexanedicarboxylic acid and high boiling glycols such as 1,4-cyclohexanedimethanol, it is difficult to remove the glycol from the polymerization mixture during the build-up phase of the reaction and only low molecular weight polymers with inherent viscosity (I.V.) values of less than 0.4 are generally obtained. Such low I.V. polymers are generally not useful as adhesives for bonding fabric, plastic, metal, or wood substrates. However, according to the present invention, it has been found that small amounts of a low boiling co-glycol can be used in the polymerization mixture to make polymers with I.V. values substantially higher than 0.4. The high molecular weight copolyesters formed by this process have been found to be quite useful as adhesives for a variety of substrates. In the bonding of fabrics and other heat sensitive substrates, it is desirable to have adhesives which will melt and bond at temperatures of 120.degree. C. or less.
Several poly(tetramethylene terephthalate) and poly(hexamethylene terephthalate) copolyesters are known and are being used as adhesives. However, it is generally not possible to use these two families of polyester adhesives at bonding temperatures less than about 120.degree. C. Patents relating to these terephthalate-based polyester adhesives include U.S. Pat. Nos. 4,094,721 and 4,419,507.
It is also known in the art to prepare low molecular weight polymers from adipic acid and 1,4-cyclohexanedimethanol. Such materials have been disclosed to be used as an additive along with other agents in the transfer printing of cotton/polyester fabrics (German Patent Applications Nos. 2,754,175 and 2,745,597). These low molecular weight polymers have also been reacted with diisocyanates to provide polymers which are used as additives in standard epoxy resins (U.S. Pat. No. 4,000,214).
We are not aware of any prior art concerned with high molecular weight poly(1,4-cyclohexylenedimethylene adipate) polymers.